I've been having a really strange problem with my starter (this is on a 88 TII if it makes any difference). Most of the time it will work fine, but sometimes it will not stop turning when I release the key from the Start position. It will keep turning even if I turn the ignition all the way to Off and remove the key. The dash lights and other electrical things do turn off when I put the ignition to Off. The engine is turning while the starter is still going, so the lever in the starter is still pushing the gear out to the flywheel. I have to disconnect the battery to get the starter to stop. It stays off when I reconnect the battery unless I turn the key to Start again.

Does this sound like a bad starter solenoid?

 

I would check the starter solenoid. Sounds like it's getting stuck (though it's rare for it to stick on). Also test the ignition switch with a meter, making sure that the START position is not intermittantly connecting (though I doubt that as well).

 

OK, I pulled the solenoid off of an old starter that I have (motor burned out, but solenoid still seemed to work OK). The solenoid body separates in to two pieces. The piston that pulls the gear arm back is covered with some kind of grease. It's all gunked up and old looking, so I want to clean it off and replace with some new stuff. Does anyone know what kind of grease this is (white lithium maybe)?

 

Thoroughly clean all of the gunk from both the piston and the inside bore of the solenoid (carb or brake cleaner will work) and then reassemble without any lube.

 

I cleaned my solenoid w/ brake cleaner... however, it doesnt seem like the soleniod will be the culprit in your case... I would think that it was your switch malfunctioning...

 

^ I'd agree. The piston return spring in the solenoid is pretty stout, and it's unlikely that it wouldn't return the piston to its at-rest position and disconnect the starter.